End closure for tubular bodies



- Jan. 12', 1943. s. BERGSTEIN' 2,307,913

END CLOSURE FOR TUBULAR BODIES Filed Dec. 11, 1940 2 Sheets-Sheet l IINVENTOR. SAMUEL flats-s TE/N.

ATTORNEYS.

Jan. 12;, 1943. s. BERGSTEIN END CLOSURE FOR TUBULARBODIES Filed Dec.11, 1940 2 Sheets-Sheet 2 INVENTOR. 5A MUEL Bakes rs/1v.

MQPW

AT TO R N EYS Patented Jan. 12, 1943 T OFFICE END CLOSURE FOR TUBULARBODIES Samuel Bergstein, Cincinnati, Ohio, assignor to Robert Morrisstein, trustees Bergstein and Frank David Berg- Application December 11,1940, Serial No. 369,636 3 Claims. 229-39) My invention relates morespecifically to end closure for cartons made of rigid or semi-rigidmaterial such as boxboard and the like, of which the folding carton suchas used for inner tubes, etc., is a good example.

Such carton consists essentially of a body retained in tubular form by aglued seam or joint, with flaps at the end to provide the closure. Inthe art there are many types of end closures known and used, some beingarrangements of tucks and flaps, and other various arrangements of flapswhich are designed to be adhered or pasted together to form the closure,and so on.

It is an object of my invention to provide an improved type of enclosureadapted to such cartons, which can readily be folded into closedposition by hand without the need of machinery. It is a further objectof my invention to provide a closure that when so formed into closedposition will hold dependably under shipping and handling conditions,providing a tight and tamper-proof end seal, without the need foradhesive and the like.

Figure 1 shows my preferred form of flat blank.

Fig. 2 shows the blank in Fig. 1 after having been secured into tubularform, in which fiat tubular form the carton is shipped to the user.

Fig. 3, is a perspective showing the carton of Fig. 2 after having beensquared up.

Fig. 4 is an enlarged perspective showing the first step in forming theend closure.

Fig. 5 shows the closure in partly assembled condition.

Fig. 6 is a fragmentary side elevation showing the final closure.

. Fig. 7 shows an alternate style blank of my invention, and

Fig. 8 shows the blank in sure partially formed.

Referring now to Fig. 1. The blank shown has four main panels, I, 2, 3and 4, panel 4 having articulated thereto a glue flap 5. Articulated tothe main body panels by lines of fold la, 2a, 3a and 4a, are end closureflaps lb, 21),

Fig. 7 with the clo- 3b, and 4b. As shown, these end closure flaps arearticulated to each other along lines of fold marked lo, 20, 3c and 4c.

Articulated to end closure flap lb, by lines of fold, are two smallextending tabs 9-9. Ad-

jacent the lines of fold 2c and 3c, are slotted or cut-away portions8-8.

In the blank shown in Fig. 1 the end closure of the opposite end of thecarton is the same, and since this is the case there is no need todescribe it in detail, it being understood that my invention as hereindisclosed is adapted to form the closure on the end of a tubularcontainer, whether one or both ends, as desired.

Fig. 2 shows the blank in Fig. 1 after having been folded and glued, theglue seam 5 and its continuations having been secured to panel I and theflaps thereof, as illustrated. This operation is carried out by standardequipment which forms no part of this invention, and the folded flattubular carton in the form shown in Fig. 2 is the condition in which thecarton is shipped to the point where the packing or filling is to bedone.

Fig. 3 shows one end of the flat tubular carton of Fig. 2 after beingsquared up into open position.

Fig. 4 shows one of the first steps of performing the end closure. Thesmall tabs 9 are folded inwardly to underlie the panel lb to which theyare articulated, and as shown inFig. 4, with these tabs held in foldedposition, the flap lb is brought inwardly and at the same time theopposite flap 3b is pressed inwardly. This causes the intermediate flaps2b and 4b to fold inwardly along their respective diagonal fold lines 2dand 4d as illustrated. It can be seen that the further reverse foldingof these intermediate flaps along the diagonal lines therein, forms sortof a pocket to the flap 3b and it is towards this space that theextending flap lb with the infolded tabs 9 is being guided, as seen inFig. 5.

Fig. 6 shows the closure complete. The slots 8-8 are so located thatthey only register with the tabs 99, when all the flaps have beenbrought into position substantially at right angles to the main bodypanels of the carton body. Therefore, when the closure illustrated inFig. 5 is carried through to the final point shown in Fig. 6, with theflaps all in flush position, the tabs spring through the openings orslots, retaining the closure in flat position transverse the end of thetubular structure, permanently and securely.

Fig. 7 shows an alternate style blank made according to my invention. Itis similar in many respects to the preferred style except it will benoted that the .panel lb is separated from the adjoining panels, and isnot connected thereto by lines of articulation. Also it will be seenthat panel 2b and panel 4b which are the ones with the slots locatedtherein, have only one diagonal line of fold 2d or 4d respectivelytherein, and the assembly of this end closure can be readily seen fromthe succeeding drawings Fig. 8. Here again it will be noted that panel3b in connection with the two adjoining panels 4b and 2b forms a pocketby the reverse folding along the diagonal lines, the separate panel l-bwith the tabs 9 thereon being introduced into the pocket as the flapsare brought together and closed down into closed position, and once theflaps have reached the position substantially at right angle to the mainbody panel of the carton, here again the tabs thereupon register withthe slots, to retain the closure securely.

In passing, some details in connection with the closure above describedmight be noted. One of these is that the register between the tab andthe slot can be extremely close, so that the tab is not engaged by goingthrough the slot until the flaps are actually in the completelyflattened position desired for a tight end closure. This is possiblebecause there is enough flexibility in this closure to permit the flapsto be depressed slightly below the line of right angles to the main bodypanel, that is, slightly into the end of the body of the containeritself, andthen released.

This permits extremely close register, and since the closeness of thisregister determines the tightness of the end closure, as far as itslying flush across'theend of the tubular structure, it is an importantfeature.

Another point that might be noted is that I prefer to-have the tabarticulated along lines of foldwhich are slightly, tapered or on a bias,thereby facilitating the entry of the flap to which the tabs arearticulated, into the opposite pocket formed of the remaining flaps.

It is obvious that variations can be made without departing'from thespirit or scope of my invention. For example, instead of beingcompletely cut-away portions, the slots might be formed by cutting thedesired area on three sides'and scoring it on the fourth, so that thestock therein would swing freely when pressure was applied, to permitinterlocking with the tab. All such variations are contemplated, theinherent features of the invention being set forth in the claims.

It can thus be seen that I have provided a simple, very effective andsecure end closure for a tubular structure. Once the flap having thetabs thereon is started into position between the opposite flap and theinfolded triangular portions of the intermediate flaps,- a straightdownward pressure is all that is required to guide the flap, the closurebeing, in that sense, self-aligning. There is no further manipulationrequired to" provide the interlocking of the tabs with the slots,because immediately upon reaching the position at right angles to themain body panel or slightly below that, the tabs automaticallyreleaseinto theslots, and the closure is complete It .will further benoted that while such a closure starts externally, that is, bymanipulations which begin on the outer flap of the carton, forexample,the finished closure when completed is locked internally, and inpractice it is almost impossible to disengage this closure, withoutmutilating or destroying the container itself. If my closure-forexample, is used at both ends of a container, the container, oncelooked, is tamper-proof and as rigidly closed on the ends as'if theflapswere' securely adhered, and the minimumof manual manipulations,because this is accomplished with the tabs automatically release uponregistering with the slots provided.

Having thus described my invention what I claim as new and novel anddesire to secure by Letters Patent, is:

1. A container having a tubular body comprising wall members, each ofsaid wall members having articulated thereto an end closure flap, saidend closure flaps constituting opposed pairs, each flap of one opposedpair being articulated to the same flap of the other pair, having slotstherein adjacent the lines of the said articulation, and also havingdiagonally arranged score lines proceeding from points on said lines ofarticulation adjacent the line of juncture of said flap of said otherpair and extending toward the ends of the flaps of the first mentionedpair, whereby when said flaps are folded into a position substantiallyat right angles to said body wall members, the flaps of said firstmentioned pair will be folded back on themselves on said diagonal scorelines, said flap of said other pair lying above the flaps of said firstmentioned pair, the second flap of said other pair being longer than theaforementioned flaps and having adjacent its end sidewise extendingtabs, said longer flap being adapted to be inserted beneath its opposedflap and between it and the folded back portions of the flaps of thefirst mentioned pair, the parts being so dimensioned that when all flapsare folded down to a position substantially at right angles to the bodywalls of the carton the said tabs will enter the-said slots and form alock for the carton.

2. The structure claimed in claim 1 in which the'flaps of the firstmentioned pair are articulated-to the last mentioned, longer flap, andare rovided with additional diagonally arranged score lines to permitthefolding of all flaps to a position substantially at rightangles tothe body walls of the carton. V

3. A'container having a' tubular body comprising four wall members, eachof said wall-members having articulated thereto an end closure flap, oneof said end closure flaps having the adjacent flaps articulated to it,one at each side, said adjacent; flaps each bearing a diagonal scoreline proceeding from a point adjacent saidfirst mentionedflap, and theline of articulation of said flaps to their respective wall, andextending diagonally outwardly away fromsaid first mentioned flapwhereby all three of said flaps may be folded inwardly, toa position"substantially at right an glesto the said wall members, said" adjacentflaps folding back upon themselves on said diagonal'score'lines, saidadjacent flaps having slots formed therein adjacent their lines ofarticulation to said first mentioned flap, theremaimng or fourth closureflap of said carton being greater in length than the other'fiaps" sothat its projecting end may be inserted beneath thefirst mentioned flapduring the closureof said carton, and said fourth flap having adjacentits outer end a 'pair of tongues projecting sidewise, said tongues beingso positioned that when saidcarton is closed with said projecting end ofsaid fourth flap inserted beneath said first mentioned flap, saidtongues will enter said slots in saida'djacent flaps to hold saidcarton'closed.

SAMUEL BERGSTEIN.

